Concern Around Hackers Using DHCP Pool
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@scottalanmiller said:
Threat level: zero.
Incoming Phone Call From Agitated Employee Level: 15
If some device (IOT device, malicious employee, etc) is sitting on his network grabbing every IP address they can, that eventually becomes a Denial of Service attack. While "only" an inconvenience to him and the employee(s) / devices that has to wait on a valid IP address, it still leads to phone calls and agitated users.
If the only cost is my time, I'll choose mitigation every time. Although I agree with your assessment that if you're using a known insecure IOT device on your network, get it off!
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@brianlittlejohn said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@Dashrender said in Unifi switch - tagged traffic issues:
Unifi's guest still uses all the production network services.
What's the concern there?
Licensing could be an issue if you are running Windows DHCP/DNS.
That was covered in the other thread and makes sense. But doesn't address the "hacking" concern.
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@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@brianlittlejohn said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@Dashrender said in Unifi switch - tagged traffic issues:
Unifi's guest still uses all the production network services.
What's the concern there?
Licensing could be an issue if you are running Windows DHCP/DNS.
That was covered in the other thread and makes sense. But doesn't address the "hacking" concern.
Didn't see the other thread.
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@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said:
Threat level: zero.
Incoming Phone Call From Agitated Employee Level: 15
It's a small office. And no one would EVER do this. The thread level is totally non-existent.
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@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said:
Threat level: zero.
Incoming Phone Call From Agitated Employee Level: 15
It's a small office. And no one would EVER do this. The thread level is totally non-existent.
So nobody would EVER call if they came into the office and their computer couldn't get on the network?
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@dafyre said in Concern Around Hackers Using DHCP Pool:
If the only cost is my time, I'll choose mitigation every time. Although I agree with your assessment that if you're using a known insecure IOT device on your network, get it off!
So you'd like to waste your time mitigating a threat that is a million to one would ever happen and has effectively no penalty even if it does happen?
This is the "shoot yourself in the face today to avoid a headache tomorrow" problem. More effort to prevent something than if the thing actually happened - and a thing that has no real world chance of happening.
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@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said:
Threat level: zero.
Incoming Phone Call From Agitated Employee Level: 15
It's a small office. And no one would EVER do this. The thread level is totally non-existent.
So nobody would EVER call if they came into the office and their computer couldn't get on the network?
No one would EVER attack a network in this way. It's ridiculous to discuss as an attack vector in a small office.
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Everyone truly believes that customers of a doctor's office will sit in the office, and knowing that they are doing something that will hurt no one and have no useful effect, take the time to try to tie up IP addresses? I'm lost, what motivation do you think people have for this? Why would someone do this? How many of you have seen people do this in the real world?
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@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
Everyone truly believes that customers of a doctor's office will sit in the office, and knowing that they are doing something that will hurt no one and have no useful effect, take the time to try to tie up IP addresses? I'm lost, what motivation do you think people have for this? Why would someone do this? How many of you have seen people do this in the real world?
Sad, but true. I had someone doing this on a network with 8k IP addresses. I also have reason to believe they were causing problems at some of my (formerly) local customers as well (but no proof on their neworks).
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@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
Everyone truly believes that customers of a doctor's office will sit in the office, and knowing that they are doing something that will hurt no one and have no useful effect, take the time to try to tie up IP addresses? I'm lost, what motivation do you think people have for this? Why would someone do this? How many of you have seen people do this in the real world?
Sad, but true. I had someone doing this on a network with 8k IP addresses. I also have reason to believe they were causing problems at some of my (formerly) local customers as well (but no proof on their neworks).
And that person was a customer sitting in the office of a small business where everyone involved could see him and could have him arrested? 8K DHCP on a single lease scope seems like a lot.
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And taking up 8K IPs addresses had no effect but to cause a momentary inconvenience that only took a minute to fix?
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@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
And taking up 8K IPs addresses had no effect but to cause a momentary inconvenience that only took a minute to fix?
Not after I fixed the issue.
And yes, 8k was a lot. This one was a student network, so he could have been anywhere on campus doing it.
The off campus places he was doing it to were small shops and yes he could have been caught. Fortunately for him, he was not.
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@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
And taking up 8K IPs addresses had no effect but to cause a momentary inconvenience that only took a minute to fix?
Not after I fixed the issue.
And yes, 8k was a lot. This one was a student network, so he could have been anywhere on campus doing it.
The off campus places he was doing it to were small shops and yes he could have been caught. Fortunately for him, he was not.
A school is not comparable to a small medical office. Clearly this isn't applicable to the case at hand.
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@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
And taking up 8K IPs addresses had no effect but to cause a momentary inconvenience that only took a minute to fix?
Not after I fixed the issue.
And yes, 8k was a lot. This one was a student network, so he could have been anywhere on campus doing it.
The off campus places he was doing it to were small shops and yes he could have been caught. Fortunately for him, he was not.
A school is not comparable to a small medical office. Clearly this isn't applicable to the case at hand.
School? No. Small local coffee shop? Maybe. (This was one of the local businesses that I supported)
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@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
And taking up 8K IPs addresses had no effect but to cause a momentary inconvenience that only took a minute to fix?
Not after I fixed the issue.
And yes, 8k was a lot. This one was a student network, so he could have been anywhere on campus doing it.
The off campus places he was doing it to were small shops and yes he could have been caught. Fortunately for him, he was not.
A school is not comparable to a small medical office. Clearly this isn't applicable to the case at hand.
School? No. Small local coffee shop? Maybe. (This was one of the local businesses that I supported)
A small local coffee shop had 8K IPs in their DHCP scope? Seriously? It's an off campus student network in a coffee shop?
I'm not following this.
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@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@dafyre said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
And taking up 8K IPs addresses had no effect but to cause a momentary inconvenience that only took a minute to fix?
Not after I fixed the issue.
And yes, 8k was a lot. This one was a student network, so he could have been anywhere on campus doing it.
The off campus places he was doing it to were small shops and yes he could have been caught. Fortunately for him, he was not.
A school is not comparable to a small medical office. Clearly this isn't applicable to the case at hand.
School? No. Small local coffee shop? Maybe. (This was one of the local businesses that I supported)
A small local coffee shop had 8K IPs in their DHCP scope? Seriously? It's an off campus student network in a coffee shop?
I'm not following this.
I had two clients I am speaking of.
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A school with 8k IPs on that subnet (where I was able to mitigate what the student was doing) -- as you said, no longer relevant to the discussion.
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A coffee shop with ~250 IPs on their subnet where I was not able to mitigate what the student was doing (simple Wifi router, lol), and got phone calls a couple of times a week for a while where I reminded them to reboot the AP.
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@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
Everyone truly believes that customers of a doctor's office will sit in the office, and knowing that they are doing something that will hurt no one and have no useful effect, take the time to try to tie up IP addresses? I'm lost, what motivation do you think people have for this? Why would someone do this? How many of you have seen people do this in the real world?
Even if they did, just shut the guest network off then. Essentially one click of the mouse and it's done. I still don't see the point of a whole separate VLAN because if someone does it there you will still have to do the same thing.
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@dafyre said in Concern Around Hackers Using DHCP Pool:
I had two clients I am speaking of.
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A school with 8k IPs on that subnet (where I was able to mitigate what the student was doing) -- as you said, no longer relevant to the discussion.
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A coffee shop with ~250 IPs on their subnet where I was not able to mitigate what the student was doing (simple Wifi router, lol), and got phone calls a couple of times a week for a while where I reminded them to reboot the AP.
I see. But I'd still say that random people at a coffee shop are not similar to guests in a medical office. It's not socially related. Someone "wanting to mess with some wifi" would target a coffee shop where the wifi is a big deal and part of the business. The guest wifi in a medical office is just a bonus for people, no one is getting medical attention just to sit and use the wifi while waiting.
I'm going to go with "still not applicable", but it is closer at least. But have some empathy for the people in the situation here - absolutely no one is ever (and maybe has never in the history of the Internet) bothered to attack a small medical office in this way.
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@stacksofplates said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
Everyone truly believes that customers of a doctor's office will sit in the office, and knowing that they are doing something that will hurt no one and have no useful effect, take the time to try to tie up IP addresses? I'm lost, what motivation do you think people have for this? Why would someone do this? How many of you have seen people do this in the real world?
Even if they did, just shit the guest network off then. Essentially one click of the mouse and it's done. I still don't see the point of a whole separate VLAN because if someone does it there you will still have to do the same thing.
Yeah, separating them still leaves both networks open for attack. If someone attacks the guest network, you have to deal with that the same. And if something goes wrong or an internal user attacks the main network, that's still got the problem. I don't see any real risk mitigation, just time being spent to make things more complex.
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@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
@stacksofplates said in Concern Around Hackers Using DHCP Pool:
@scottalanmiller said in Concern Around Hackers Using DHCP Pool:
Everyone truly believes that customers of a doctor's office will sit in the office, and knowing that they are doing something that will hurt no one and have no useful effect, take the time to try to tie up IP addresses? I'm lost, what motivation do you think people have for this? Why would someone do this? How many of you have seen people do this in the real world?
Even if they did, just shit the guest network off then. Essentially one click of the mouse and it's done. I still don't see the point of a whole separate VLAN because if someone does it there you will still have to do the same thing.
Yeah, separating them still leaves both networks open for attack. If someone attacks the guest network, you have to deal with that the same. And if something goes wrong or an internal user attacks the main network, that's still got the problem. I don't see any real risk mitigation, just time being spent to make things more complex.
Interesting typo I made there
